RSA_set_default_method, RSA_get_default_method, RSA_set_method, RSA_get_method,
RSA_PKCS1_OpenSSL, RSA_flags, RSA_new_method - select RSA method
#include <openssl/rsa.h>
The following functions have been deprecated since OpenSSL 3.0, and can be
hidden entirely by defining
OPENSSL_API_COMPAT with a suitable version
value, see
openssl_user_macros(7):
void RSA_set_default_method(const RSA_METHOD *meth);
const RSA_METHOD *RSA_get_default_method(void);
int RSA_set_method(RSA *rsa, const RSA_METHOD *meth);
const RSA_METHOD *RSA_get_method(const RSA *rsa);
const RSA_METHOD *RSA_PKCS1_OpenSSL(void);
int RSA_flags(const RSA *rsa);
RSA *RSA_new_method(ENGINE *engine);
All of the functions described on this page are deprecated. Applications should
instead use the OSSL_PROVIDER APIs.
An
RSA_METHOD specifies the functions that OpenSSL uses for RSA
operations. By modifying the method, alternative implementations such as
hardware accelerators may be used. IMPORTANT: See the NOTES section for
important information about how these RSA API functions are affected by the
use of
ENGINE API calls.
Initially, the default RSA_METHOD is the OpenSSL internal implementation, as
returned by
RSA_PKCS1_OpenSSL().
RSA_set_default_method() makes
meth the default method for all RSA
structures created later.
NB: This is true only whilst no ENGINE has
been set as a default for RSA, so this function is no longer recommended. This
function is not thread-safe and should not be called at the same time as other
OpenSSL functions.
RSA_get_default_method() returns a pointer to the current default
RSA_METHOD. However, the meaningfulness of this result is dependent on whether
the ENGINE API is being used, so this function is no longer recommended.
RSA_set_method() selects
meth to perform all operations using the
key
rsa. This will replace the RSA_METHOD used by the RSA key and if
the previous method was supplied by an ENGINE, the handle to that ENGINE will
be released during the change. It is possible to have RSA keys that only work
with certain RSA_METHOD implementations (e.g. from an ENGINE module that
supports embedded hardware-protected keys), and in such cases attempting to
change the RSA_METHOD for the key can have unexpected results.
RSA_get_method() returns a pointer to the RSA_METHOD being used by
rsa. This method may or may not be supplied by an ENGINE
implementation, but if it is, the return value can only be guaranteed to be
valid as long as the RSA key itself is valid and does not have its
implementation changed by
RSA_set_method().
RSA_flags() returns the
flags that are set for
rsa's
current RSA_METHOD. See the BUGS section.
RSA_new_method() allocates and initializes an RSA structure so that
engine will be used for the RSA operations. If
engine is NULL,
the default ENGINE for RSA operations is used, and if no default ENGINE is
set, the RSA_METHOD controlled by
RSA_set_default_method() is used.
RSA_flags() returns the
flags that are set for
rsa's
current method.
RSA_new_method() allocates and initializes an
RSA structure so
that
method will be used for the RSA operations. If
method is
NULL, the default method is used.
typedef struct rsa_meth_st
{
/* name of the implementation */
const char *name;
/* encrypt */
int (*rsa_pub_enc)(int flen, unsigned char *from,
unsigned char *to, RSA *rsa, int padding);
/* verify arbitrary data */
int (*rsa_pub_dec)(int flen, unsigned char *from,
unsigned char *to, RSA *rsa, int padding);
/* sign arbitrary data */
int (*rsa_priv_enc)(int flen, unsigned char *from,
unsigned char *to, RSA *rsa, int padding);
/* decrypt */
int (*rsa_priv_dec)(int flen, unsigned char *from,
unsigned char *to, RSA *rsa, int padding);
/* compute r0 = r0 ^ I mod rsa->n (May be NULL for some implementations) */
int (*rsa_mod_exp)(BIGNUM *r0, BIGNUM *I, RSA *rsa);
/* compute r = a ^ p mod m (May be NULL for some implementations) */
int (*bn_mod_exp)(BIGNUM *r, BIGNUM *a, const BIGNUM *p,
const BIGNUM *m, BN_CTX *ctx, BN_MONT_CTX *m_ctx);
/* called at RSA_new */
int (*init)(RSA *rsa);
/* called at RSA_free */
int (*finish)(RSA *rsa);
/*
* RSA_FLAG_EXT_PKEY - rsa_mod_exp is called for private key
* operations, even if p,q,dmp1,dmq1,iqmp
* are NULL
* RSA_METHOD_FLAG_NO_CHECK - don't check pub/private match
*/
int flags;
char *app_data; /* ?? */
int (*rsa_sign)(int type,
const unsigned char *m, unsigned int m_length,
unsigned char *sigret, unsigned int *siglen, const RSA *rsa);
int (*rsa_verify)(int dtype,
const unsigned char *m, unsigned int m_length,
const unsigned char *sigbuf, unsigned int siglen,
const RSA *rsa);
/* keygen. If NULL built-in RSA key generation will be used */
int (*rsa_keygen)(RSA *rsa, int bits, BIGNUM *e, BN_GENCB *cb);
} RSA_METHOD;
RSA_PKCS1_OpenSSL(),
RSA_PKCS1_null_method(),
RSA_get_default_method() and
RSA_get_method() return pointers to
the respective RSA_METHODs.
RSA_set_default_method() returns no value.
RSA_set_method() returns a pointer to the old RSA_METHOD implementation
that was replaced. However, this return value should probably be ignored
because if it was supplied by an ENGINE, the pointer could be invalidated at
any time if the ENGINE is unloaded (in fact it could be unloaded as a result
of the
RSA_set_method() function releasing its handle to the ENGINE).
For this reason, the return type may be replaced with a
void
declaration in a future release.
RSA_new_method() returns NULL and sets an error code that can be obtained
by
ERR_get_error(3) if the allocation fails. Otherwise it returns a
pointer to the newly allocated structure.
The behaviour of
RSA_flags() is a mis-feature that is left as-is for now
to avoid creating compatibility problems. RSA functionality, such as the
encryption functions, are controlled by the
flags value in the RSA key
itself, not by the
flags value in the RSA_METHOD attached to the RSA
key (which is what this function returns). If the flags element of an RSA key
is changed, the changes will be honoured by RSA functionality but will not be
reflected in the return value of the
RSA_flags() function - in effect
RSA_flags() behaves more like an
RSA_default_flags() function
(which does not currently exist).
RSA_new(3)
All of these functions were deprecated in OpenSSL 3.0.
The
RSA_null_method(), which was a partial attempt to avoid patent
issues, was replaced to always return NULL in OpenSSL 1.1.1.
Copyright 2000-2021 The OpenSSL Project Authors. All Rights Reserved.
Licensed under the Apache License 2.0 (the "License"). You may not use
this file except in compliance with the License. You can obtain a copy in the
file LICENSE in the source distribution or at
<
https://www.openssl.org/source/license.html>.